2D氧掺杂石墨烯负载0D球状渐变至2D片状TiO_(2)可控制备及光催化特性

Controllable Preparation and Photocatalytic Properties of 2D Oxygen Doped Graphene Supported 0D Spherical Gradual to 2D Flake TiO_(2)

以浓硫酸、高锰酸钾和双氧水作为氧化剂,以钛酸四丁酯、乙酸和双氧水为原料,可控制备不同比例氧掺杂石墨烯(OG)负载TiO_(2)纳米球、渐变状、纳米片的不同维度的复合材料。使用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅里叶变换红外(FTIR)光谱仪、紫外-可见光(UV-Vis)吸收光谱仪和X射线光电子能谱仪(XPS)等对复合样品进行了表征及分析。以活性染料X3B作为降解对象,研究了不同维度复合材料的光催化特性。结果表明,复合材料从0D/2D结构渐变至2D/2D结构,TiO_(2)与2D氧掺杂石墨烯复合程度更加紧密,光催化性能逐步提升,2D氧掺杂石墨烯负载TiO_(2)纳米片(TS-OG)效果最好,该样品在90 min模拟太阳光下对X3B降解率达到了99.5%。OG的深层次氧化使得其边缘、内部存在大量含氧官能团(—COOH、—OH等),而浓硫酸处理在复合过程中起到了关键作用,有助于TiO_(2)与OG产生更强的键合作用,促进了TiO_(2)表面的—OH与OG的大量含氧官能团深层次键合,使得电子传导速率增强,提高了光生电子和空穴对的分离,光催化性能显著提高,经过浓硫酸处理的TS6-OG在60 min模拟太阳光下催化降解率约是未经浓硫酸处理样品的2.7倍。

With concentrated sulfuric acid,potassium permanganate and hydrogen peroxide as oxidants,tetrabutyl titanate,acetic acid and hydrogen peroxide as raw materials,different ratios of oxygen-doped graphene(OG)supported TiO_(2)nanosphere,gradation and nanosheet composite materials with different dimensions were controllably prepared.The composite samples were characterized and analyzed by scanning electron microscope(SEM),transmission electron microscope(TEM),X-ray diffractometer(XRD),Fourier transform infrared(FTIR)spectrometer,UV-Vis absorption spectrometer and X-ray photoelectron spectrometer(XPS).With reactive dye X3B as degradation object,the photocatalytic properties of the composite materials with different dimensions were studied.The results show that the composite materials gradually change from 0D/2D structure to 2D/2D structure,the composite degree of TiO_(2)and 2D oxygen-doped graphene is closer,the photocatalytic performance is gradually improved,and the 2D oxygen-doped graphene supported TiO_(2)nanosheets(TS-OG)have the best effect.The best samples achieve 99.5%degradation rate of X3B under simulated sunlight for 90 min.The deep oxidation of OG leads to the existence of a large number of oxygen-containing functional groups(—COOH,—OH,etc.)at its edges and inside.And concentrated sulfuric acid treatment plays a key role in the composite process,helping TiO_(2)to produce stronger bonding with OG,promoting the stronger bonding of—OH on the surface of TiO_(2)with a large number of oxygencontaining functional groups of OG,and enhancing the electron conductivity,which improves the separation of photogenerated electrons and hole pairs,and significantly enhances the photocatalytic performance.Under simulated sunlight for 60 min,the photocatalytic degradation rate of TS6-OG treated with concentrated sulfuric acid is about 2.7 times higher than that of the sample treated without concentrated sulfuric acid.